From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: [PATCH] Promise 'stex' driver Date: Fri, 21 Jul 2006 03:07:24 +0200 Message-ID: <20060721010724.GB24176@suse.de> References: <44BFF539.4000700@garzik.org> <1153439728.4754.19.camel@mulgrave> <44C01CD7.4030308@garzik.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from ns.virtualhost.dk ([195.184.98.160]:40533 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S1030426AbWGUBH3 (ORCPT ); Thu, 20 Jul 2006 21:07:29 -0400 Content-Disposition: inline In-Reply-To: <44C01CD7.4030308@garzik.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Jeff Garzik Cc: James Bottomley , Ed Lin , "linux-scsi@vger.kernel.org" , hch , linux-kernel , akpm , promise_linux On Thu, Jul 20 2006, Jeff Garzik wrote: > James Bottomley wrote: > >On Thu, 2006-07-20 at 17:27 -0400, Jeff Garzik wrote: > >>Since _no individual SCSI driver_ uses the block layer > >>tagging, it is likely that some instability and core kernel > >>development > >>will occur, in order to make that work. > > > >That's not quite true: 53c700 and tmscsim both use it ... I could with > >the usage were wider, but at least 53c700 has pretty regular and > >constant usage ... enough I think to validate the block tag code (it's > >been using it for the last three years). > > Not for the case being discussed in this thread, adapter-wide tags. That just means the map is shared, otherwise there should be little if any difference. > AFAICS, no file in include/scsi/* or drivers/scsi/* ever calls > blk_queue_init_tags() with a non-NULL third arg. grpe again, it's in scsi_tcq.h. > The block tagging capability being discussed here is poorly validated > due to overall underuse, and its never been used in SCSI AFAIK. It has and is, James uses it every day! -- Jens Axboe